The ElementContainer is a container for Elements, and can be used as a standard Python list. Instances of this class are returned by methods that can return more than one element (for example: Element.get_children(), TestSuite.all_elements()).
The main purpose of ElementContainers is verification of a document's structure. If your solution wants to check if the second <div> contains something, and the student's submission only has one <div>, then this would cause an IndexError. When getting indexes that go out of bounds, the ElementContainer will return an empty element instead. Empty elements will make checks fail, and rightfully so because the element doesn't exist even though it should, but the suite itself won't crash.
Get the Element at a specific index of the container. In case there aren't enough elements in the container this returns an empty element instead.
Alternatively, you can also use the []-operator. Slicing is also supported (e.g. all_divs[start:stop:step]).
def get(index: int) -> Element| Name | Description | Required? | Default |
|---|---|---|---|
index |
The index at which to look for an element. | ✔ |
Let's say we want to perform checks on two <div>s inside of the <body>. That means we first have to get references to those <div>s, which means they should exist.
However, only one single <div> is present in the student's code. This means the second_div variable will contain an empty element, but checks can still be performed on it.
<html>
<body>
<div>
...
</div>
</body>
</html>suite = HtmlSuite(content)
body = suite.element("body")
# Get an ElementContainer with all divs inside of the body
all_divs = body.get_children("div")
# Using .get
first_div = all_divs.get(0)
# Using []-operator
second_div = all_divs[1] # Doesn't exist, so it will be empty
# Checks can still be performed on the second div, but they will fail
second_div.exists()
second_div.attribute_exists("something")The ElementContainer comes with a few checks relating to the amount of elements found.
Check that a container has at least a certain amount of elements.
def at_least(amount: int) -> Check| Name | Description | Required? | Default |
|---|---|---|---|
amount |
The minimum amount of elements allowed. | ✔ |
suite = HtmlSuite(content)
body = suite.element("body")
table = body.get_child("table")
# Get an ElementContainer with all trs inside of the table
all_trs = table.get_children("tr")
# Check that there are at least 4 trs inside of the table
all_trs.at_least(4)Check that a container has at most a certain amount of elements.
def at_most(amount: int) -> Check| Name | Description | Required? | Default |
|---|---|---|---|
amount |
The maximum amount of elements allowed. | ✔ |
suite = HtmlSuite(content)
body = suite.element("body")
# Get an ElementContainer with all divs inside of the body
all_divs = body.get_children("div")
# Check that there are no more than 5 divs
all_divs.at_most(5)Check that a container has exactly a certain amount of elements.
def exactly(amount: int) -> Check| Name | Description | Required? | Default |
|---|---|---|---|
amount |
The exact amount of elements allowed. | ✔ |
suite = HtmlSuite(content)
body = suite.element("body")
# Get an ElementContainer with all p's inside of the body
all_ps = body.get_children("p")
# Check that there are exactly 3 paragraphs
all_ps.exactly(3)Check that all of the elements inside of this container match a function. The argument should be a function that maps an Element onto a Check. If the container is empty, this check will also fail.
Shorthand for all_of combined with a generator expression.
def all(func: Callable[[Element], Check]) -> Check| Name | Description | Required? | Default |
|---|---|---|---|
func |
The function to run for every element. | ✔ |
suite = HtmlSuite(content)
table = suite.element("table")
# Check that the <table> only contains <tr> elements, nothing else
table.get_children().all(lambda i: i.has_tag("tr"))Check that any of the elements inside of this container matches a function. The argument should be a function that maps an Element onto a Check. If the container is empty, this check will also fail.
Shorthand for any_of combined with a generator expression.
def any(func: Callable[[Element], Check]) -> Check| Name | Description | Required? | Default |
|---|---|---|---|
func |
The function to run for every element. | ✔ |
suite = HtmlSuite(content)
table = suite.element("table")
# Check that the <table> contains at least one element that has exactly one child
table.get_children().any(lambda i: i.get_children().exactly(1))